Ice tray



Feb. 14, 1950 J. H. ROETHEL ICE TRAY Filed May 22, 1948 INVENTOR. J2? /xRad/ha Patented Feb. 14, T9550 UNITED STATES PATENT OFFICE' RoethelEngineering Corporation,

Detroit,

Mich, a corporation of Michigan Application May 22,1948, Serial No.28,541

3 Claims.

This invention relates to liquid freezing trays and particularly to atray of the general type having a. pan-like receptacle within which icecubes or blocks of frozen substances are molded through the medium ofgrid or division members connecting the side walls of the tray.

An object of the invention is to provide an ice tray or the like whichmay be molded as a unit from plastic material, such as polyethyleneplastic or the like, to provide transverse grid or divider membersjoined to the bottom and side walls of the tray, and in which the bottomof the tray may be made relatively thin and capable of providing maximumfreezing contact with the "evaporator shelf, the improved constructionbeing such as to permit flexing or twisting of the receptacle so as toeasily loosen or eject the ice blocks.

A further object of the invention is to form the pan or receptacle ofthe tray and its transverse grid or divider members in one piece fromplastic material, preferably polyethylene or equivalent material, thegrid members of the tray being tapered so as to increase in thicknesstoward the bottom of the tray and the side walls of the tray decreasingin thickness toward the bottom of the tray, thus enabling a thin bottomto be used while facilitating removal of the ice cubes when the tray isflexed or torsionally twisted, the improved construction having thefurther advantage of assisting in maintaining the tray in proper shape.

Still another object of the invention is to provide the upper edges ofthe side walls of the tray receptacle with notches or depressed portionswhich not only serve as overflow openings to control the height of thewater level in the tray when filled but also increase the flexibility ofthe tray to facilitate bending or flexing thereof ,when removing the icecubes.

tion it is to be understood that the invention is not limited in itsapplication to the details of construction and arrangement of partsillustrated in the accompanying drawings, since the invention is capableof other embodiments and of being practiced or carried out in variousways. Also it is to be understood that the phraseology or terminologyemployed herein is for the purpose of description and not of limitation.

In the drawings there is illustrated, by way of example, an ice traycomprising a pan-like receptacle adapted to contain water andconstructed with a series of transverse grid or dividing membersintegrally connecting the side walls of the tray or receptacle togetherand by means of which a number of ice cubes or blocks may be producedwhen the tray is supported within the ice freezing compartment of arefrigerator.

The pan-like receptacle I0 is generally rectangular in shape and in thepresent instance is relatively narrow to produce a single row of icecubes or blocks corresponding in widths to the width of the receptacle.The pan or receptacle i0 is molded in one piece from polyethylene orequivalent plastic material to provide a fiat bottom ll terminating inparallel upright side walls l2 and rear and front upright walls l3 and Hrespectively which are integral with the bottom and extend continuouslyaround the four sides of the tray. The bottom H of the receptacle isrelatively thin and after merging into the side and end walls [2, l3 andM the latter preferably increase in thickness in the direction of theupper edges thereof. These side and end walls are sloped or inclined inan upward direction so as to facilitate the removal of the ice cubesfrom the tray. The end walls I3 and i4 terminate at their upper edges inoutwardly extending flange portions I5 and [6 respectively which arepreferably of increased thickness and serve the purpose of handles orhand grips which not only may be grasped to remove the tray from therefrigerator compartment but also may be grasped to facilitate flexingor twisting of the tray in removing or ejecting the cubes therefrom.

The pan shaped receptacle [0 is molded to provide a number of transversegrid or divider members I! which are integral with the bottom it as wellas the side walls l2. In the present iiistance the tray is formed withseven grid or divider members I! which together with the end wallsdivide the receptacle into spaces for the production of eight ice cubesor blocks. It will be understood that the tray may be formed with Beforeexplaining in detail the present invenw a smaller or larger number ofdivider strips for the purpose of producing the desired number of icecubes. I prefer to utilize an injection molding process for producing inone piece the receptacle l and transverse grid or divider members I1. Itwill be noted that each of the divider members or strips I1 is generallywedge shaped in cross section. The lower edges lid of the divider stripsare joined to the bottom H by curved fillets which in effect producetransverse stiffening ribs effective to reinforce the receptacle andenable the bottom II to be made quite thin so as to reduce the rate offreezing. Each of the divider strips or members l1 diminishes inthickness toward the upper edge llb thereof so as to have tapering sidewalls. By this construction the side walls of each ice cube space formedby two of the divider strips ll flare or taper upwardly therebyfacilitating the ejection of the frozen ice cubes therefrom. It will beapparent, therefore, that by flaring the walls I2 as well as the walls11 of each freezing space the ice cube may be forced outwardly throughthe top opening of this space very easily. As illustrated in Fig. 1, theends of the divider strips I! are joined to the side walls i2 by curvedfillets l8 which in effect form ribs which are continuations of thecorresponding rib-like portions along the lower edges of the members I!and which in like manner reinforce the tray and assist in maintainingthe shape thereof after continued use.

In the present embodiment of the invention the upper edges 12a of theside walls of the tray receptacle are formed with notches or depressedportions [9, a pair of these notches being provided centrally of theside wall portions of each freezing space. The notches l9 are ofsuitable depth and preferably arcuate in configuration, and thesenotches serve the two purposes of controlling the height of the waterlevel in the tray when filled and of increasing somewhat the flexibilityof the side walls of the tray so as to facilitate bending of the traywhen it is desired to re= move the ice cubes therefrom in this manner.By providing the overflow openings or notches IS the water level in thetray after filling may be maintained at a level correspondingsubstantially to the bottoms of the notches, and hence when the waterfreezes and expands upwardly the frozen ice cubes or blocks will notproject upwardly beyond the upper edges of the divider members l1 norwill the ice blocks be joined across the tops of these divider strips soas to interfere with the quick ejection of the ice cubes from the tray.

As previously stated, the receptacle l0 including the divider or gridmembers I! is formed in a single injection molding operation frompolyethylene plastic or equivalent material. Polyethylene isparticularly adapted for use in the fabrication of the present ice trayfor the reason that this material has a wax-like surface which isnon-wettable by water and, hence, inhibits the adherence of the icethereto. Polyethylene is not only tough, flexible and substantiallyunbreakable, even under conditions of hard usage, but will also yieldunder tension in order to compensate for the expansion of ice uponfreezing. After formation of the ice cubes in the tray the cubes may bereadily loosened from the bottom and side walls of the freezing spacesupon grasping the flange portions I and I6 or the ends of the pan andtorsionally twisting, flexing or bending the same. The cubes may also beremoved individually from the freezing spaces by placing the fingersupon the upper edges of the freezing space and the thumbs against thebottom of the space and then applying pressure with the thumbs againstthe bottom of the freezing space so as to force the ice cube out of thepan. This method of ejecting the cubes individually from the pan isfacilitated by reason of the thin flexible character of the bottom wallll of the pan and the taper given to all four sides of the freezingspace.

I prefer to form the bottom II of the pan or receptacle ill with a wallthickness as low as approximately .030 of an inch. Wall thicknessesranging from approximately .030 to .040 of an inch are satisfactory forthe bottom of the pan, it being understood that the wall thickness ofthe upright sides and end of the pan increase progressively anduniformly so as to have substantially greater thickness at the upperedges thereof. The wall thicknesses of the upper edges of the side andend walls of the pan may range from approximately .050 to .093 of aninch. This construction together with the rib-like fillets formed alongthe bottom and side edges of the divider strips I! afford sufficientform-sustaining rigidity to the tray regardless of the unusual thinnessgiven to the bottom thereof. The divider members H may taper to athickness at the upper edges thereof corresponding substantially to thethickness of the bottom ii. Although the thickness of the bottom I i ofthe tray receptacle preferably falls within approximately the foregoingrange. it will be understood that a wall thickness from approximately.020 to .065 of an inch will give good results.

I claim:

1. A liquid freezing tray comprising a generally rectangular pan-shapedmember formed with a bottom and surrounding upright outer side walls, aplurality of transverse divider strips integrally joined along theirbottom and end edges to the bottom and to an opposed pair of said sidewalls, each strip diminishing in thickness from the lower edge to theupper edge thereof, the upper edges of said opposed outer side wallsbeing formed with a plurality of notches.

2. A liquid freezing device comprising a pan shaped tray and gridmembers dividing the tray into a plurality of liquid freezing spaces,the upper edge of an outer side of said tray being formed with depressedportions for controlling the level of liquid in said spacesindependently of one another when the tray is filled.

' 3. A liquid freezing device comprising a panshaped tray having abottom and surrounding upright side walls, and grid means dividing thetray into a plurality of separate liquid freezing compartments, theupper edges of a pair of opposed outer side walls having notches forcontrolling the level of liquid in said compartments each independentlyof the others when the tray is filled.

JOHN H. ROETHEL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,820,221 Geyer Aug. 25, 19312,287,972 Carney June 30, 1942 2,433,211 Gits Dec. 23, 1947 2,452,846Flynn Nov. 2, 1948

